This invention relates to dental mirror stems, in general, and to a new and improved stem for coupling with a handle to provide a mirror used in dentistry, in particular.
As is well known and understood, dental mirrors are used extensively in the practice of dentistry, and basically consist of a dental mirror stem (or xe2x80x9cmirror portionxe2x80x9d) attached to a handle, and either by a cone-socket insertion or by a thread joining the two sections. As is also well known, such mirror portion includes a mirrored, reflective surface, within a frame or holder, which together then get coupled with the handle. With the more expensive xe2x80x9cfront-surfacexe2x80x9d mirror, the reflected image appears at the xe2x80x9ctopxe2x80x9d of the mirror; with a less expensive xe2x80x9crear-surfacexe2x80x9d mirror, the reflected image appears at the xe2x80x9cbottomxe2x80x9d of the mirror.
As is additionally appreciated, the major advantage of the xe2x80x9cfront-surfacexe2x80x9d mirror is the much clearer image it presents, as the dentist is not looking through a layer of glass before reaching the reflective surface; with the xe2x80x9crear-surfacexe2x80x9d mirror, on the other hand, its primary advantages follow from its lower cost, and that it does not scratch as easily.
More-and-more in the practice of dentistry, today, air-abrasive technology is being employed to drill very fine preparations on teeth. Experience has shown, however, that the particles of teeth thus dislodged, along with the particles of aluminum oxide wearing off the dental drill, fly about the mouth, striking the glass mirrorxe2x80x94and to the extent that the surface etching which results (particularly at high pressure and speed) oftentimes so deteriorates the reflected image as to make the mirror essentially unusable. Nevertheless, the advantage of this new technology continues to extend into the profession, and chiefly because the resultant air-blasting produces substantially no micro-cracks in the dental enamel, because its method of operation is much less painless than associated with the previously employed dental drill, and because its careful use can allow extremely fine openings to be made in the tooth to check to see if there is any decay present.
One type of solution that has been proposed to protect the glass mirror surface is to temporarily lie over it a plastic substrate which itself incorporates a light reflective surface. Then, whether the dental mirror be fabricated of fibercore material to allow its use in electrosurgery without being electrically conductive, or whether the mirror is used of a metal fabrication sufficiently strong to exert pressure in retracting the cheek and tongue, it is the plastic substrate that gets damaged by the debris flying about the mouth, and not the glass surface to which the plastic substrate is secured. After the coarse drilling with the air-abrasive apparatus is finished, the plastic substrate is merely pulled away, and the clearer producing image of the glass surface alone is employed for allowing the dentist to inspect the work done and to complete the procedure.
While these types of xe2x80x9cdisposable mirror surfacesxe2x80x9d serve their purpose adequately well in this environment, analysis has shown that a problem continues to exist. In particular, for example, the glass reflecting surface is positioned within a frame or holder of the mirror stem, leaving a surrounding channel between the side edge of the glass mirror and the wall of the frame in defining the diameter of the mirror and in establishing the configuration of the reflective surface. Testing has shown that no matter how much the dental mirror may be disinfected, or sterilized in an autoclave, the debris flying about the mouth that gets captured in this channel, stays and collects there. Even though the rim area defined by the side wall of the frame is quite fine, analysis has shown that there continues to be retained in the channel remnants of the grinding debris, elements of the patient""s own tissue cells, bacteria and other organisms. A consideration of these circumstances illustrates the existence of a possible hygienic problem area which it would be desirable to eliminate.
It is an object of the present invention, therefore, to provide a new and improved dental mirror which is characterized by the absence of this channel surrounding the mirror-reflective surface.
It is an object of the invention, also, to provide such a mirror which continues to be able to accept the temporary securement of these plastic substrates in protecting the glass mirror during the coarse grinding actions of dental treatmentxe2x80x94whether the mirror be of the xe2x80x9cfront-surfacexe2x80x9d or xe2x80x9crear-surfacexe2x80x9d variety.
It is another object of the invention to eliminate this debris-capturing channel, while, at the same time, permitting the plastic reflective surface to be temporarily securable on either or both of the upper and lower surfaces of the frame in which the glass mirror is inserted, to assist the dentist in the treatment of the patient.
It is yet another object of the invention to eliminate these debris-capturing and collecting channels, whether the resulting mirror be provided with a threaded end for joining the dental mirror stem to its handle, whether the join between the two be of an otherwise cone-socket arrangement, whether the combination so formed be used as a xe2x80x9cfront-surfacexe2x80x9d or xe2x80x9crear-surfacexe2x80x9d mirror, and regardless of whether the mirror be formed of the more typical metal handle composition, or whether it be of a plastic material for use in electrosurgery.
As will become clear from the following description, these objectives are attained through the invention of a dental mirror stem including a shaft having first and second ends, and a substantially circular disc having flat upper and lower surfaces extending to a side surface of the disc in defining the diameter of the disc and in establishing the configuration of the disc as being substantially and continuously flat. Means are then provided to secure the first end of the shaft to the disc, and with a plastic substrate having a reflective surface then secured to at least one of the upper and lower surfaces of the disc. In this manner, the previous side wall of the prior art frame defining the channel is eliminated; also, the probability of tooth particle damage to a glass mirror surface as the dislodged tooth particles fly about is obviated by the use of the plastic substrate. As will become more particularly clear, by having a substantially circular disc without the channel formed in the frame or holder where the reflective surface seats, the capture and collection of the grinding debris is thereby avoided.
In a preferred embodiment of the invention to be described, the shaft of the dental mirror stem secures to a side surface of the substantially circular disc, so as to permit plastic substrates to be temporarily secured, as by an adhesive coupling, to either or both of the upper and lower surfaces of the disc. As will be appreciated, such construction permits the shaft and substantially circular disc to be formed by a metal stamping processxe2x80x94whether, or not, the handle of the mirror is similarly so formed. In a further embodiment of the invention, the shaft is bent around to the lower surface of the substantially circular disc to be secured there, in a manner akin to the dental mirror stem used in the prior art. In either event, however, the capturing channel for debris present in designs of the type utilized today will be seen to be eliminated.
In other words, the dental mirror stem with the substrate attached is used where the coarse drilling is to take place, with the attendant debris, tissue cells, bacteria, etc. being present, but without any channel being there to capture them. After that is completed, the conventional xe2x80x9cfrontxe2x80x9d or xe2x80x9crearxe2x80x9d surface mirror is employed for the fine finishing of the dental treatment, without fear of extensively damaging the mirror surface. The substrate of the dental mirror stem is peeled away, the stem is sterilized in any appropriate manner, and a new substrate attached for the next patient usage; however, no collected material is retained for transmittal to that next patient.